title: Effects of short-term transdermal estradiol administration on plasma levels of nitric oxide in postmenopausal women.
abstract: OBJECTIVE
  To assess the effects of short-term transdermal E2 administration on nitric oxide (NO) plasma levels in postmenopausal women.
  
  
  METHODS
  Randomized, placebo-controlled trial.
  
  
  METHODS
  Healthy volunteers in an academic research environment.
  
  
  METHODS
  Twenty-eight healthy postmenopausal women.
  
  
  METHODS
  Transdermal administration of E2 (100 microg/d) or placebo on days 1 and 4 of a 1-week treatment regimen.
  
  
  METHODS
  Serum concentrations of E2 and plasma concentrations of NO stable oxidation products were assessed on day 1, before placement of the patch, and subsequently on days 2, 3, and 6.
  
  
  RESULTS
  The mean concentration of NO metabolites on days 2, 3, and 6 was significantly greater in the E2 group (40.08+/-15.42 micromol/L, 38.05+/-18.82 micromol/L, and 42.03+/-16.81 micromol/L on days 2, 3, and 6, respectively) compared with both baseline levels (23.07+/-5.79 micromol/L) and the placebo group (23.51+/-4.06 micromol/L, 21.64+/-4.72 micromol/L, and 21.81+/-4.46 micromol/L on days 2, 3, and 6, respectively).
  
  
  CONCLUSIONS
  During a 1-week treatment regimen with transdermal E2, plasma levels of NO in postmenopausal women were significantly higher than baseline levels on days 2, 3, and 6. This suggests that the effect of estrogens on NO synthesis is rapid and that it is maintained with repeated administration.
authors.affiliation: Department of Obstetrics and Gynecology, University of Bari, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Cicinelli
authors.forename: L J
authors.initials: LJ
authors.lastname: Ignarro
authors.forename: L M
authors.initials: LM
authors.lastname: Schönauer
authors.forename: M G
authors.initials: MG
authors.lastname: Matteo
authors.forename: P
authors.initials: P
authors.lastname: Galantino
authors.forename: G
authors.initials: G
authors.lastname: Balzano
mesh_terms: D000279:Administration, Cutaneous; D004958:Estradiol / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000097:blood*; D009573:Nitrites / Q000097:blood; D017698:Postmenopause / Q000097:blood*; D013997:Time Factors
chemical_list: D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D004958:Estradiol